Method for forming hybrid article

ABSTRACT

A hybrid article is disclosed including a coating disposed on and circumscribing the lateral surface of a core having a core material. The coating includes about 35% to about 95% of a first metallic material having a first melting point, and about 5% to about 65% of a second metallic material having a second melting point lower than the first melting point. A method for forming the hybrid article is disclosed including disposing the core in a die, forming a gap between the lateral surface and the die, introducing a slurry having the metallic materials into the gap, and sintering the slurry, forming the coating. A method for closing an aperture of an article is disclosed including inserting the hybrid article into the aperture. Closing the aperture includes brazing the hybrid article to the article, welding the aperture with the hybrid article serving as weld filler, or a combination thereof.

CROSS REFERENCE TO RELATED APPLICATIONS

This application relates to and claims the benefit of U.S. patentapplication Ser. No. 14/966,788, filed Dec. 11, 2015, entitled “HybridArticle, Method for Forming Hybrid Article and Method for ClosingAperture,” the disclosures of which are incorporated by reference intheir entirety.

FIELD OF THE INVENTION

The present invention is directed to hybrid articles, methods forforming hybrid articles and methods for closing apertures. Moreparticularly, the present invention is directed to hybrid articles,methods for forming hybrid articles and methods for closing apertureswherein the hybrid articles include a core material and a coating havingtwo metallic materials with different melting points.

BACKGROUND OF THE INVENTION

Hard-to-weld (HTW) alloys, such as nickel-based superalloys and certainaluminum-titanium alloys, due to their gamma prime and various geometricconstraints, are susceptible to gamma prime strain aging, liquation andhot cracking. These materials are also difficult to join when the gammaprime phase is present in volume fractions greater than about 30%, whichmay occur when aluminum or titanium content exceeds about 3%. As usedherein, an “HTW alloy” is an alloy which exhibits liquation, hot andstrain-age cracking, and which is therefore impractical to weld.

These HTW alloys may be incorporated into components of gas turbineengines such as airfoils, blades (buckets), nozzles (vanes), shrouds,combustors, rotating turbine components, wheels, seals, 3d-manufacturedcomponents with HTW alloys and other hot gas path components.Incorporation of these HTW alloys may be desirable due to often superioroperational properties, particularly for certain components subjected tothe most extreme conditions and stresses.

Manufacturing processes and repairs of components incorporating HTWalloys, such as the closing of apertures left open during castingprocesses, is difficult to achieve using standard techniques, as thesetechniques may damage the HTW alloys or introduce materials which wouldbe weakened or cracked by the elevated temperatures to which thecomponents are subjected to. By way of example, typical brazingtechniques are unsuitable because typical braze materials or elementsare incorporated into the component which may not meet operationalrequirements.

BRIEF DESCRIPTION OF THE INVENTION

In an exemplary embodiment, a hybrid article includes a core and acoating. The core includes a lateral surface and a core material. Thecoating is disposed on and circumscribes the lateral surface. Thecoating includes about 35% to about 95% of a first metallic materialhaving a first melting point, and about 5% to about 65% of a secondmetallic material having a second melting point. The first melting pointis higher than the second melting point.

In another exemplary embodiment, a method for forming a hybrid articleincludes disposing a core in a die. The core includes a lateral surface.A gap is formed between the lateral surface and the die. The gapcircumscribes the lateral surface. A slurry is introduced into the gap.The slurry includes a first metallic material having a first meltingpoint, and a second metallic material having a second melting point. Thefirst melting point is higher than the second melting point. The lateralsurface is coated with the slurry. The slurry is sintered to form acoating circumscribing the lateral surface, forming the hybrid article.The coating includes about 35% to about 95% of the first metallicmaterial and about 5% to about 65% of the second metallic material.

In another exemplary embodiment, a method for closing an aperture of anarticle includes inserting a hybrid article into the aperture. Thehybrid article includes a core and a coating. The core includes alateral surface and a core material. The coating is disposed on andcircumscribes the lateral surface. The coating includes about 35% toabout 95% of a first metallic material having a first melting point, andabout 5% to about 65% of a second metallic material having a secondmelting point. The first melting point is higher than the second meltingpoint. The aperture is closed. Closing the aperture includes a techniqueselected from the group consisting of brazing the hybrid article to thearticle, welding the aperture with the hybrid article serving as a weldfiller, and combinations thereof.

Other features and advantages of the present invention will be apparentfrom the following more detailed description of the preferredembodiment, taken in conjunction with the accompanying drawings, whichillustrate, by way of example, the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a hybrid article, according to anembodiment of the present disclosure.

FIG. 2 is a schematic view of the formation of a hybrid article,according to an embodiment of the present disclosure.

FIG. 3 is a sectional view along lines 3-3 of the core and die of FIG.2, according to an embodiment of the present disclosure.

FIG. 4 is a sectional view along lines 4-4 of the core, die, and slurryof FIG. 2, according to an embodiment of the present disclosure.

FIG. 5 is a sectional view along lines 5-5 of the core, die, and slurryof FIG. 2, according to an embodiment of the present disclosure.

FIG. 6 is a sectional view of an article and hybrid articles, accordingto an embodiment of the present disclosure.

Wherever possible, the same reference numbers will be used throughoutthe drawings to represent the same parts.

DETAILED DESCRIPTION OF THE INVENTION

Provided are exemplary hybrid articles, methods for forming hybridarticles and methods for closing apertures. Embodiments of the presentdisclosure, in comparison to articles and methods not utilizing one ormore features disclosed herein, decrease costs, increase processcontrol, increase reparability, improve mechanical properties, improveelevated temperature performance, increase weldability, or a combinationthereof.

Referring to FIG. 1, in one embodiment, a hybrid article 100 includes acore 102 and a coating 104. The core 102 includes a lateral surface 106and a core material 108. The coating 104 is disposed on the lateralsurface 106. The coating 104 includes a first metallic material 110 anda second metallic material 112.

In one embodiment, the core 102 includes an average diameter of fromabout 0.25 mm to about 50 mm, alternatively from about 0.5 mm to about30 mm, alternatively from about 0.5 mm to about 15 mm, alternativelyfrom about 0.5 mm to about 5 mm, alternatively from about 0.5 mm toabout 3 mm, alternatively from about 1 mm to about 2 mm.

In another embodiment, the coating 104 includes an average coatingthickness of from about 0.1 mm to about 10 mm, alternatively from about0.25 mm to about 7.5 mm, alternatively from about 0.5 mm to about 5 mm,alternatively from about 0.5 mm to about 2.5 mm, alternatively fromabout 0.5 mm to about 2 mm, alternatively from about 0.5 mm to about 1mm.

The hybrid article 100 may include any suitable article cross-sectionalconformation 114, including, but not limited to, a circle (shown), anellipse, an oval, a triangle, a rounded triangle, a square, a roundedsquare, a rectangle, a rounded rectangle, a pentagon, a roundedpentagon, a hexagon, a rounded hexagon, or a combination thereof. Thecore 102 may include any suitable core cross-sectional conformation 116,including, but not limited to, a circle (shown), an ellipse, an oval, atriangle, a rounded triangle, a square, a rounded square, a rectangle, arounded rectangle, a pentagon, a rounded pentagon, a hexagon, a roundedhexagon, or a combination thereof. The article cross-sectionalconformation 114 may be the same conformation as the corecross-sectional conformation 116 or a different conformation. In oneembodiment, the core is a wire. In a further embodiment, the core is anelectrically conductive wire.

The coating 104 may include any suitable amount of the first metallicmaterial 110 and the second metallic material 112. In one embodiment,the coating including about 35% to about 95% of the first metallicmaterial, alternatively, about 45% to about 85% of the first metallicmaterial, alternatively about 35% to about 55% of the first metallicmaterial, alternatively about 55% to about 75% of the first metallicmaterial, alternatively about 75% to about 95% of the first metallicmaterial. In another embodiment, the coating including about 5% to about65% of the second metallic material, alternatively, about 15% to about55% of the second metallic material, alternatively about 55% to about25% of the second metallic material, alternatively about 25% to about45% of the second metallic material, alternatively about 45% to about65% of the second metallic material. In a further embodiment, thecoating 104 consists essentially of the first metallic material 110 andthe second metallic material 112, excluding impurities forming less thanabout 3% of the coating 104, alternatively less than about 2% of thecoating 104, alternatively less than about 1% of the coating 104.

In one embodiment, the first metallic material 110 includes a firstmelting point, and the second metallic material 112 includes a secondmelting point, wherein the first melting point is higher than the secondmelting point. The first melting point may be from about 2,380° F. toabout 2,700° F., alternatively from about 2,400° F. to about 2,600° F.,alternatively from about 2,450° F. to about 2,550° F., alternativelyfrom about 2,475° F. to about 2,525° F. The second melting point may befrom about 1,400° F. to about 2,375° F., alternatively from about 1,450°F. to about 2,300° F., alternatively from about 1,500° F. to about2,200° F., alternatively from about 1,550° F. to about 2,150° F.,alternatively from about 1,600° F. to about 2,100° F.

The core material 108 may be any suitable material, including, but notlimited to, a superalloy, a nickel-based superalloy, a cobalt-basedsuperalloy, an iron-based superalloy, a hard-to-weld (HTW) alloy, arefractory alloy, GTD 111, GTD 444, HAYNES 188, INCONEL 738, MAR-M-247,Rene 108, Rene 142, Rene 195, Rene N2, or a combination thereof.

The first metallic material 110 may be any suitable material, including,but not limited to, a superalloy, a nickel-based superalloy, acobalt-based superalloy, an iron-based superalloy, a hard-to-weld (HTW)alloy, a refractory alloy, GTD 111, GTD 444, HAYNES 188, INCONEL 738,MAR-M-247, Rene 108, Rene 142, Rene 195, Rene N2, or a combinationthereof. The first metallic material 110 may be the same material as thecore material 108 or a different material.

The second metallic material 112 may be any suitable material,including, but not limited to, a braze alloy, DF-4B, BNi-2, BNi-5 (AMS4782), BNi-9, or a combination thereof.

As used herein, “DF-4B” refers to an alloy including a composition, byweight, of about 14% chromium, about 10% cobalt, about 3.5% aluminum,about 2.5% tantalum, about 2.75% boron, about 0.05% yttrium, and abalance of nickel.

As used herein, “BNi-2” refers to an alloy including a composition, byweight, of about 3% iron, about 3.1% boron, about 4.5% silicon, about 7%chromium, and a balance of nickel.

As used herein, “BNi-5” and “AMS 4782” refer to an alloy including acomposition, by weight, of about 10% silicon, about 19% chromium, and abalance of nickel.

As used herein, “BNi-9” refers to an alloy including a composition, byweight, of about 15% chromium, about 3% boron, and a balance of nickel.

As used herein, “GTD 111” refers to an alloy including a composition, byweight, of about 14% chromium, about 9.5% cobalt, about 3.8% tungsten,about 4.9% titanium, about 3% aluminum, about 0.1% iron, about 2.8%tantalum, about 1.6% molybdenum, about 0.1% carbon, and a balance ofnickel.

As used herein, “GTD 444” refers to an alloy including a composition, byweight, of about 7.5% cobalt, about 0.2% iron, about 9.75% chromium,about 4.2% aluminum, about 3.5% titanium, about 4.8% tantalum, about 6%tungsten, about 1.5% molybdenum, about 0.5% niobium, about 0.2% silicon,about 0.15% hafnium, and a balance of nickel.

As used herein, “HAYNES 188” refers to an alloy including a composition,by weight, of about 22% chromium, about 22% nickel, about 0.1% carbon,about 3% iron, about 1.25% manganese, about 0.35% silicon, about 14%tungsten, about 0.03% lanthanum, and a balance of cobalt.

As used herein, “INCONEL 738” refers to an alloy including acomposition, by weight, of about 0.17% carbon, about 16% chromium, about8.5% cobalt, about 1.75% molybdenum, about 2.6% tungsten, about 3.4%titanium, about 3.4% aluminum, about 0.1% zirconium, about 2% niobium,and a balance of nickel.

As used herein, “MAR-M-247” refers to an alloy including a composition,by weight, of about 5.5% aluminum, about 0.15% carbon, about 8.25%chromium, about 10% cobalt, about 10% tungsten, about 0.7% molybdenum,about 0.5% iron, about 1% titanium, about 3% tantalum, about 1.5%hafnium, and a balance of nickel.

As used herein, “Rene 108” refers to an alloy including a composition,by weight, of about 8.4% chromium, about 9.5% cobalt, about 5.5%aluminum, about 0.7% titanium, about 9.5% tungsten, about 0.5%molybdenum, about 3% tantalum, about 1.5% hafnium, and a balance ofnickel.

As used herein, “Rene 142” refers to an alloy including a composition,by weight, of about 6.8% chromium, about 12% cobalt, about 6.1%aluminum, about 4.9% tungsten, about 1.5% molybdenum, about 2.8%rhenium, about 6.4% tantalum, about 1.5% hafnium, and a balance ofnickel.

As used herein, “Rene 195” refers to an alloy including a composition,by weight, of about 7.6% chromium, about 3.1% cobalt, about 7.8%aluminum, about 5.5% tantalum, about 0.1% molybdenum, about 3.9%tungsten, about 1.7% rhenium, about 0.15% hafnium, and a balance ofnickel.

As used herein, “Rene N2” refers to an alloy including a composition, byweight, of about 7.5% cobalt, about 13% chromium, about 6.6% aluminum,about 5% tantalum, about 3.8% tungsten, about 1.6% rhenium, about 0.15%hafnium, and a balance of nickel.

Referring to FIG. 2, in one embodiment, a method for forming the hybridarticle 100, includes disposing the core 102 in a die 200. Referring toFIGS. 2 and 3, a gap 202 is formed between the lateral surface 106 andthe die 200, and the gap 202 circumscribes the lateral surface 106.Referring to FIGS. 2 and 4, a slurry 204 is introduced into the gap 202,the slurry including the first metallic material 110 and the secondmetallic material 112, and coating the lateral surface 106. Referring toFIGS. 2 and 5, the slurry 204 circumscribes the lateral surface 106.Referring again to FIG. 2 the slurry 204 is sintered to form the coating104 circumscribing the lateral surface 106, forming the hybrid article100. The slurry 204 may include a binder gel. In one embodiment, theslurry 204 includes a viscosity sufficient to adhere to the core 102until the slurry 204 is sintered to form the coating 104.

Sintering the slurry 204 to form the coating 104 may include heating theslurry 204 with a heating element 206. The heating element 206 may beany suitable heating element, including, but not limited to, an oven. Inone embodiment, heating the slurry 204 includes heating the slurry 204to a sintering temperature. The sintering temperature may be anysuitable temperature, including, but not limited to, a sinteringtemperature of from about 1,500° F. to about 2,375° F., alternativelyfrom about 1,600° F. to about 2,350° F., alternatively from about 1,700°F. to about 2,325° F., alternatively from about 1,800° F. to about2,300° F., alternatively from about 1,850° F. to about 2,250° F. Inanother embodiment, heating the slurry 204 to the sintering temperatureincludes maintaining the slurry 204 at the sintering temperature for asintering duration. The sintering duration may be any suitable duration,including, but not limited to, a duration of from about 5 minutes toabout 150 minutes, alternatively from about 10 minutes to about 120minutes, alternatively from about 15 minutes to about 90 minutes.Sintering the slurry 204 to form the coating 104 may include heating theslurry 204 under air, under inert gas, under vacuum, or a combinationthereof.

In one embodiment, the core 102 is a wire. In another embodiment, thecore 102 is passed through the die 200. Passing the core 102 through thedie 200 may be a continuous process. In yet another embodiment, the die200 is part of a coating apparatus for the production of a weldingelectrode, such as, but not limited to, a shielded metal arc weldingelectrode. In another embodiment, the die 200 is a component of anextrusion press.

In one embodiment, the slurry 204 is introduced under elevated pressure.As used herein, “elevated pressure” indicates a pressure greater thanatmospheric pressure external to the die 200. The elevated pressures maybe any suitable pressure, including, but not limited to, a pressuresufficient to fully coat the lateral surface 106 with the slurry 204 asthe core 102 passes through the die 200.

The hybrid article 100 may be finished by any suitable finishingtechnique, including, but not limited to, heating, polishing, brushing,tip cleaning, sizing, chemically treating, or a combination thereof.Sizing the hybrid article 100 may include removing at least one portionof the hybrid article 100 to reduce the length of the hybrid article 100to a predetermined length. The predetermined length may be any suitablelength. Removing at least one portion of the hybrid article 100 mayinclude severing the at least one portion of the hybrid article 100 atany suitable angle with respect to the length of the hybrid article 100,including, but not limited to, an orthogonal angle or an angle matchingthe surface of an article into which the hybrid article 100 is to beinserted.

Referring to FIG. 6, in one embodiment, a method for closing an aperture602 of an article 600 includes inserting the hybrid article 100 into theaperture 602, and closing the aperture 602. Closing the aperture 602includes brazing the hybrid article 100 to the article 600, welding theaperture 602 with the hybrid article 100 serving as a weld filler, or acombination thereof.

Closing the aperture 602 may form a hermetic seal. In one embodiment,when the aperture 602 is closed, the terminus 604 of the hybrid article100 is about even with the surface 606 of the article 600. In anotherembodiment, when the aperture 602 is closed, the terminus 604 isdivergent from the surface 606 of the article 600. As used herein,“about even” indicates that the terminus 604 is less than 0.3 mm removedfrom the surface 606 of the article 600, and “divergent” indicates thatthe terminus 604 is at least 0.3 mm removed from the surface 606 of thearticle 600.

In one embodiment, the article 600 is a turbine component. The article600 may be any suitable turbine component, including, but not limitedto, a hot gas path component, an airfoil, a bucket (blade), a nozzle(vane), a shroud, a combustor, or a combination thereof.

In one embodiment, brazing the hybrid article 100 to the article 600includes brazing the hybrid article 100 to a hard-to-weld (HTW) alloy.In another embodiment, welding the aperture 602 includes employing awelding apparatus 608 to perform a welding technique. The weldingtechnique may be any suitable welding technique, including, but notlimited to, gas tungsten arc welding, shielded metal arc welding, plasmaarc welding, laser beam welding, electron beam welding, or a combinationthereof.

The hybrid article 100 may be used as a weld filler for any suitablewelding application which uses a welding technique incorporating a weldfiller. Suitable welding applications include, but are not limited, toclosing apertures in superalloy components, closing apertures in HTWalloy components, filling cavities in superalloy components, fillingcavities in HTW alloy components, repairing superalloy components,repairing HTW alloy components, joining a first component and a secondcomponent, wherein at least one of the first component and the secondcomponent includes a superalloy, joining a first component and a secondcomponent, wherein at least one of the first component and the secondcomponent includes an HTW alloy, or a combination thereof. The weldingtechnique may include, but is not limited to, gas metal arc welding, gastungsten arc welding, shielded metal arc welding, plasma arc welding,laser beam welding, electron beam welding, or a combination thereof.

In one embodiment, the core material 108 of the hybrid article 100includes the same material composition as a substrate material 610 ofthe article 600 which defines the aperture 602. In another embodiment,the core material 108 of the hybrid article 100 includes a materialcomposition distinct from the substrate material 610 of the article 600which defines the aperture 602. In this context, the core material 108includes the same material composition as the substrate material 610 ifthe material composition is about the same and any variations areinsufficient to have a material effect on the properties of thematerial, whereas the core material 108 of the hybrid article 100includes a material composition distinct from the substrate material 610if the material composition is not about the same or if the variationsestablish a material effect on the properties of the material.

While the invention has been described with reference to a preferredembodiment, it will be understood by those skilled in the art thatvarious changes may be made and equivalents may be substituted forelements thereof without departing from the scope of the invention. Inaddition, many modifications may be made to adapt a particular situationor material to the teachings of the invention without departing from theessential scope thereof. Therefore, it is intended that the inventionnot be limited to the particular embodiment disclosed as the best modecontemplated for carrying out this invention, but that the inventionwill include all embodiments falling within the scope of the appendedclaims.

What is claimed is:
 1. A method for forming a hybrid article,comprising: disposing a core in a die, the core including a lateralsurface; forming a gap between the lateral surface and the die, the gapcircumscribing the lateral surface; introducing a slurry into the gap,the slurry including a first metallic material having a first meltingpoint, and a second metallic material having a second melting point, thefirst melting point being higher than the second melting point; coatingthe lateral surface with the slurry; and sintering the slurry to form acoating circumscribing the lateral surface, forming the hybrid article,the coating including about 35% to about 95% of the first metallicmaterial and about 5% to about 65% of the second metallic material. 2.The method of claim 1, wherein disposing the core in the die includespassing the core through the die.
 3. The method of claim 2, whereinpassing the core through the die is a continuous process.
 4. The methodof claim 1, wherein disposing the core in the die includes disposing thecore in a coating apparatus for the production of a welding electrode.5. The method of claim 1, wherein disposing the core in the die includesdisposing the core in an extrusion press.
 6. The method of claim 1,wherein sintering the slurry to form the coating includes heating theslurry to a sintering temperature of from about 1,500° F. to about2,375° F. for a sintering duration of from about 5 minutes to about 150minutes.
 7. The method of claim 1, wherein sintering the slurry to formthe coating includes heating the slurry with a heating element.
 8. Themethod of claim 1, wherein the slurry includes a viscosity sufficient toadhere to the core until the slurry is sintered to form the coating. 9.The method of claim 1, wherein disposing the core in the die includesdisposing a wire as the core.
 10. The method of claim 1, whereinintroducing the slurry into the gap includes introducing the slurryunder elevated pressure.
 11. The method of claim 1, further includingfinishing the hybrid article.
 12. The method of claim 1, furtherincluding sizing the hybrid article to a predetermined length.
 13. Themethod of claim 1, wherein disposing the core in the die includesdisposing the core having a core cross-sectional conformation selectedfrom the group consisting of a circle, an ellipse, an oval, a triangle,a rounded triangle, a square, a rounded square, a rectangle, a roundedrectangle, a pentagon, a rounded pentagon, a hexagon, a rounded hexagon,and combinations thereof.
 14. The method of claim 1, wherein coating thelateral surface with the slurry and sintering the slurry forms thehybrid article including an article cross-sectional conformationselected from the group consisting of a circle, an ellipse, an oval, atriangle, a rounded triangle, a square, a rounded square, a rectangle, arounded rectangle, a pentagon, a rounded pentagon, a hexagon, a roundedhexagon, and combinations thereof.
 15. The method of claim 1, whereinthe core material is selected from the group consisting of at least oneof a superalloy, a nickel-based superalloy, a cobalt-based superalloy,an iron-based superalloy, a hard-to-weld (HTW) alloy, a refractoryalloy, GTD 111, GTD 444, HAYNES 188, INCONEL 738, MAR-M-247, Rene 108,Rene 142, Rene 195, and Rene N2.
 16. The method of claim 1, wherein thefirst metallic material is selected from the group consisting of atleast one of a superalloy, a nickel-based superalloy, a cobalt-basedsuperalloy, an iron-based superalloy, a hard-to-weld (HTW) alloy, arefractory alloy, GTD 111, GTD 444, HAYNES 188, INCONEL 738, MAR-M-247,Rene 108, Rene 142, Rene 195, and Rene N2.
 17. The method of claim 1,wherein the second metallic material is selected from the groupconsisting of at least one of a braze alloy, DF-4B, BNi-2, BNi-5, andBNi-9.
 18. The method of claim 1, wherein the first melting point isfrom about 2,400° F. to about 2,600° F., and the second melting point isfrom about 1,400° F. to about 2,375° F.
 19. The method of claim 1,wherein the coating further includes an average coating thickness offrom about 0.5 mm to about 5 mm.
 20. The method of claim 1, wherein thecore further includes an average diameter of from about 0.5 mm to about30 mm.